The present invention relates generally to image generating systems, and more particularly, to an image generating system employing electrically switchable holograms.
Certain image display systems typically include a display screen configured to display monochrome images. Current microdisplays are typical of display panels that are configured to display monochrome images. When a multi-color display is required, a sequence of images is displayed and illuminated sequentially with red, green, and blue lights. The switching from one image to the next is performed rapidly (e.g., at a rate faster than the response time of a human eye) so that a color image is created in the viewer""s eye due to the integration of red, green, and blue monochrome images. This allows a viewer to see a full color image generated from a display system having a display screen operable to produce only monochrome images. The display system typically includes a white light source and a rotating color wheel having red, green, and blue filters to provide color sequential illumination of a display device. However, these rotating filters are often susceptible to mechanical failures and tend to be large and noisy.
Another category of displays is based on emissive technologies such as Light Emitting Diodes (LED), Light Emitting Polymers (LEP), Organic Light Emitting Diodes (OLED), electroluminescent displays and fieldxe2x80x94emission displays. In order to provide color it is necessary to have separate red, green and blue emitters. In such devices it is advantageous if the display screen is separated into distinct red, green, and blue regions, with each region containing emissive material and drive circuitry that can be optimized for a specific wavelength range. This offers significant cost savings in fabrication by avoiding the problems of depositing different materials in close proximity to form RGB (red-green-blue) groups (e.g., RGB triads) in order that a full color high resolution display can be provided. By grouping red, green and blue emitters in separate regions of the display it is possible to provide high resolution and brightness. However, there is the problem of how the separate monochrome images can be fused into a single full color image.
A system and method for generating an image are disclosed. A system of the present invention generally comprises a display device having a plurality of display regions, each region configured for displaying a color component of the images and a display controller coupled to the display device and operable to activate the regions of the display device to display different portions of the image. The system further includes a plurality of light directing devices positioned to receive light from the regions of the display device and direct light towards an image plane and a light directing controller coupled to the light directing devices to direct light received thereby to different areas of the image plane. The areas of the image plane generally correspond to the different portions of the image displayed by the regions of the display device. The display controller and the light directing controller are coupled together such that the light directing devices direct light to the area of the image plane corresponding to the portion of the image displayed by the region of the display device.
In another aspect of the invention, a system for creating a full polychromatic image from a plurality of monochromatic images containing a portion of the full images generally comprises a plurality of light directing devices. Each of the light directing devices comprises a plurality of holographic optical elements switchable between an active state wherein light incident on the element is transmitted without substantial alteration. The holographic optical elements are operable to receive the portion of the full image and direct it to an area of an image plane corresponding generally to the portion of the image received.
A method of the present invention for generating a polychromatic image generally comprises displaying a plurality of monochromatic images components on a display device. Each image component contains a different portion of a full image. The image components are received at a plurality of light directing devices. Each of the light directing devices is configured to diffract a different wavelength light. The image components are directed to areas of an image plane. generally corresponding to the portion of the image contained within the component.
The above is a brief description of some deficiencies in the prior art and advantages of the present invention. Other features, advantages, and embodiments of the invention will be apparent to those skilled in the art from the following description, drawings, and claims.